I've seen a few apps that claim they do some kind of conditioning/deep charge/other jargon to extend the life of an iPhone battery. Is this just hokum or do I really need one of these apps to maximize the life of my battery?

Agreed. Each app is given its own sandbox limiting its access to system resources. So I think your understanding is most likely correct.
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deutschZuidApr 19 '12 at 21:56

They do nothing. You can set up a persistent iCal entry to remind you to cycle your battery free of charge. And like was said, there are no approved APIs that provide apps with such low-level access to hardware (you'll note that apps report battery percentage in 5% increments) so they cannot "condition" or "deep charge" a battery. They are nothing more than cash grabs that pray on the ignorance of users and I wish Apple curtailed their approval on the grounds that they do not bring any value to the store.
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cksumApr 20 '12 at 3:47

Be sure to go through at least one
charge cycle per month (charging the
battery to 100% and then completely
running it down).

If the app reminds you to do this every 30 days, then yes, it will improve your battery life. Unfortunately, I've seen some apps that tell you to go down to 20% and then open the app while it is charging. That isn't letting it "completely run down", and so, it would do nothing for your phone.

Besides reminding you of doing a deep cycle every 30 days, I don't see how any app could improve your battery life. If anything, it would ruin your battery life by staying running in the background.

Yes - if it's the thing that gets you to change your behavior. Whether you call it snake oil, a placebo or social engineering, changing your perception or spurring you to action is powerful and can shape your world.

No - without you doing something different, using more energy to "monitor" the battery obviously leaves less energy for the rest of the things you normally have running.

Of course a jail free app could prolong battery life, by tweaking into the system, just like Apple could (and like some android apps already do, since android has almost no management restrictions for developers). Couple things that could be done, for instance: killing apps that are known to consume batter life, or maybe turning off the screen when needed in an intelligent way.

But, as you may picture now, it's so much work that I doubt any good app will come along and I don't really know of any that do. Also, from a developer point of view, it'd be way too much time spent researching, testing and doing this for too little result, because this is already one of Apple's primary worries.

Here are few better things to do for prolonging battery life, from Apple's own list:

There are no jailbreak applications, that could tweak the system for better battery management or so. Even on the Mac platform you can only monitor but not manage or control the battery and charging mechanism.
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mspasovApr 19 '12 at 16:07